The present invention is directed to an improvement in a counter assembly such as the type of electromagnetic counting mechanism disclosed in U.S. Pat. No. 3,580,498, which is assigned to the same assignee as the present application. The counter assembly of the present invention, which for purposes of illustration is described in relation to the electromagnetic counting mechanism of U.S. Pat. No. 3,580,498, comprises an electrically operable counter module insert, a transparent viewing crystal, and an outer box-like case which interlock to provide an improved mechanical assembly. The improved assembly does not require heat setting of the crystal into the case nor is there a requirement of application of epoxy to secure the case to the frame of the module insert. The improved assembly also provides increased resistance to tampering and unauthorized disassembly because disassembly can be readily accomplished only by breaking or destroying the integrity of the crystal.
An important improvement provided by the present invention relates to the latter assembly stages of a counter assembly, such as that exemplified in U.S. Pat. No. 3,580,498, in which the counter module insert, the outer case, and the transparent viewing chrystal are assembled to produce the finished counter assembly.